Frost removing tool



June 13, 1950 R. E. HAMMOND FROST REMovING Toor.

Filed July 17, 1947 Patented June 13, 1950 UNITED STATES PATENT OFFICE 1 Claim.

This invention relates to hand tools and more particularly to an electrically heated hand tool for removing frost and the like from cold surfaces such as the cooling surfaces and coils of refrigerators and frozen food cabinets.

An important object cf my invention is to provide a simple and inexpensive hand tool by means of which accumulations of frost and ice may be quickly and effectively removed from sub-freezing surfaces with a minimum of physical effort.

Another object of my invention is to provide a tool of this character by which said frost and ice may be removed from such surfaces while the latter remain at sub-freezing temperatures.

Still another object of my invention is to provide `a heated hand tool by means of which frost and ice may be removed from surfaces Within a refrigerated space without materially increasing the temperature in said space.

A further object of my invention is to provide a tool of these characteristics shaped to prevent an accumulation of frost or ice thereon while the same is being operated to remove said frost or ice from va refrigerated surface.

Other objects and advantages of the invention will be apparent from the following description of a preferred embodiment thereof, taken in connection with the accompanying drawing, in which:

Fig. 1 is a top plan view of a hand tool incorporating my invention; and

Fig. 2 is a sectional view thereof taken substantially on the line 2-2 in Fig. 1.

As thus illustrated the tool has a, metallic tubular arm l l upon one end of which is mounted a hollow handle l2 of wood or other insulatory material shaped to be comfortably held in the hand. A ring I3 may be tted over one end of the handle in a well known manner for purposes of reinforcement. A passage I4 is drilled or otherwise formed in the other end of the handle, and within the passage and protruding therefrom is a coiled spring protective member l5 of a suitable commercial type through which extends a double strand electric cord shown generally at IB. An ordinary -male plug I1 is attached to the external end of the electric cord and the exposed portion of said cord may be provided with a heavy protective covering l'8.

From the inner end of the protective member I5 the cord extends through a hollow I9 in the handle and thence through the interior of the arm Il to a head, shown generally at 2|, within which said cord is electrically connected to an electric heating element indicated by the numeral the value of 200 and aluminum has a similar coefficient greater than 100, the value of said c0- eicient varying slightly with changes of temperature as is well known to those acquainted with the art. I prefer to use a single-piece head formed of cast aluminum or copper having the tapered parting edge 22 formed thereon as an integral part of the head.

A socket shown generally at 23 may be provided on the upper portion of the head to enclose a space 24 for receiving an end of the `arm Il. The arm may be secured to the Ihead by means of screws 25 and 26 which penetrate walls 21 of the socket and are threaded into the arm. The bottom surface of said head is flat as at 28 and the upper contours of the head are rounded to prevent an accumulation of ice and frost thereon when said frost or ice is removed from a cold surface by the tool in a manner hereinafter described.

The heating element 20 is arranged within the head along substantially the entire length of the parting edge and as close to the latter as practical. `Said heating element may be of any suitable commercial construction and, for the sake of economy and simplicity of construction, may be cast within the head as an integral part thereof. A heating element suitable for this type construction may comprise the usual loop of electrical resistance wire 29 enclosed within a tubular insulatory covering 30 composed of a magnesium oxide compound well known to the art. The lwire itself may be of chrome-nickel steel or other material having high heat resistant properties, and heat resistant porcelain beads 3| may be provided as insulation for the Wires of the electric cord adjacent the point at which the latter is attached to the heating element.

With the plug l1 connected to a source of electric current (not shown) the parting edge 22 may be pressed, with a natural and easy scraping motion, against formations of ice or frost adjacent a surface from which said frost or ice is to be cleaned. Because the heating element is in intimate association with the parting edge and the metal for-ming the edge has a high coe'icient of thermal conductivity, a minimum of thermal resistance will exist between the heating element and the line at which the parting edge engages the frost or ice. Heat will thus be conducted through said edge to the frost or ice at a maximum rate to melt the same along a thin line and cause the latter to separate from the surface. Because the rate at which heat will be conducted to said frost or ice is great, the temperature of the parting edge need not be high.

It will readily be understood that substantial-ly all of the heat generated by the heating element will be dissipated in the melting of the frost yand ice along the line of separation and thata minimum of said heat will be conducted to the surfaces being cleaned or radiated into the refrigerated space about the surfaces. Cold cooling surfaces Within refrigerators and thelike may thus be cleared of frost and ice lwith my tool While the temperatures of said surfaces and that of the refrigerated space surrounding them remain Ysubstantially unchanged.

The foregoing detailed description 'has been given for clearness of understanding only and no unnecessary limitation should be understood therefrom, but the vappending claim should be construed as broadly as permissible in view of the prior art. Y f

f A tool for removing frost from a surface comprising: a handle; a head on said handle, said head having ya flat bottom surface and rounded upper surfaces; a parting edge on said head for separating said frost from said surface; and a source of heat in intimate association with said edge for heating the latter, said edge and head being integral and being constructed of material having a coecient of thermal conductivity of a value greater than one hundred and said source of heat being disposed Within said material and parallel to said edges, said head being elongated transversely of the handle and said source of heat comprising an electrical heating element positioned in the lower front part of said head, whereby to concentrate the heat in said` parting edge, and extend substantially the full length of the latter.

ROY E. HAMMOND.

REFERENCES CITED The` following references are of record in the le of this patent: Y

UNITED STATES PATENTS Number Name Date 1,157,343 Thompson Oct. 19, 1915 1,732,502 Cox Oct. 22, 1929 1,809,718 McNeil June 9, 1931 2,062,998 Peterson Deo.1, 1936 2,107,220 Schulz Feb. l, 1938 2,263,222 Y Morris Nov. 18, 1941 2,304,559 Engesser Dec. 8, 1942 

